Aluminum is used in many kinds of manufactured products and has many applications. It can be found for example in numerous food related products such as plates, paper or foil, cans and other containers used for food packaging and wrapping. A large amount of aluminum is used especially for making beverage cans. Aluminum can also be found in lithographic sheets used by printers, in construction materials used by the commercial and residential building industry, in cosmetic powders, in paints, etc.
It is obviously desirable to recover the aluminum in the aluminum containing products after their use, for recycling purposes. Current aluminum recovery processes are mainly based on melting the products and then performing a number of separation steps on the liquefied product to recover the aluminum and/or recasting steps to produce new aluminum-based products. Such processes are energy intensive and generally produce undesirable fumes.
Dry processes and machinery for recovering certain types of materials such as plastics from used products are also known. But those processes often have a low processing rate, involve complex machinery prone to breakdowns, require intensive maintenance and adjustments, and/or require human interventions at different stages of the processing line.
U.S. Pat. No. 4,923,126 (Lodovico et al.), U.S. Pat. No. 5,769,331 (Yamagishi et al.), U.S. Pat. No. 5,855,644 (Takashima), U.S. Pat. No. 6,315,222 (Kim et al.), U.S. Pat. No. 6,663,029 (Takano et al.), U.S. Pat. No. 6,745,960 (Myo et al.), U.S. Pat. No. 6,971,594 (Polifka), U.S. Pat. No. 7,040,562 (Sawant et al.), U.S. Pat. No. 7,090,159 (Condon et al.) and Canadian patent No. 1,129,834 (Knezevich) provide examples of known processes and systems or machinery. Yet, none of them provides a complete, simple, efficient and environment friendly solution for recovering aluminum in aluminum containing products, with the recovered aluminum satisfying high quality standards at a high production rate. The aluminum recovered by the currently known systems and processes often has a poor degree of quality and/or an inconvenient form, which limits the applications where the recovered aluminum can be reused.